Quartz-iodine lamp, spectrum

Figure 1. Spectrum of quartz-iodine lamp at various integration times (in milliseconds).

Relatively insensitive to flow and temperature fluctuations non-destructive, useful with gradient elution use mercury lamp for 254 nm, and quartz-iodine lamp for 350 nm to 700 nm often a diode-array instrument is used to obtain entire UV-vis spectrum. 

Steady state photoelectrochemical behaviour of colloidal CdS For the purposes of the studies reported here, the photocurrent was taken to be the total current recorded at the ORDE from an illuminated colloidal dispersion of CdS minus the current recorded under identical condition from the same dispersion in the dark. In both studies, the photocurrents generated by CdS particles illuminated at the ORDE exhibited a wavelength dependence (action spectrum) identical to the absorption spectrum of colloidal and bulk CdS [166,168], unambiguously indicating that the observed photocurrent is due entirely to ultra-band gap photoexcited conduction band electrons. However, it should be noted that, unless stated otherwise (e.g. the action spectrum experiments), the particle suspensions of both studies were usually irradiated with white light from a 250 W quartz iodine projector lamp to maximise the photocurrents observed. 

It is advisable to periodically calibrate the sensitivity of the spectrometer by measuring the spectrum of a Planck source. For this purpose, an iodine-quartz lamp may be used to irradiate a white email as a secondary standard (D Orazio and Schrader, 1976). Further, the laser power should be monitored periodically. 

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